Electrolysis Cell and Electrode

ABSTRACT

The present proposals relate to electrolysis cells, electrodes for such cells and methods of using them. In particular the electrodes comprise a planar electrically conductive plate with at least part of one face of the plate is covered with a plurality of electrically conductive wires each of which is in electrically conductive contact with the surface of the plate along at least part of its length. The methods of the proposals relate to methods of generating oxyhydrogen gas using an electrolytic cell incorporating these electrodes.

The present proposals relate to electrolysis cells, electrodes for such cells and methods of using them. In particular these proposals relate to cells used to generate oxyhydrogen gas (known as “HHO” or “Brown's gas” under certain circumstances when the hydrogen and oxygen are present in a 2:1 ratio) e.g. by electrolysis of water.

BACKGROUND

Electrolysis of water to produce oxyhydrogen gas is well known. Oxyhydrogen gas is a mixture of oxygen (O₂) and hydrogen (H₂). Oxyhydrogen gas is also sometimes known as “HHO” or “Brown's gas” when the hydrogen and oxygen are present in the 2:1 ratio (the same ratio as in water).

Electrolysis apparatus for generating oxyhydrogen from water is also well known. For example US 2013/0015077 A1 describes an electrolysis unit including positive and negative plate electrodes interspersed with “neutral” or “passive” plates. This document also describes the use of the electrolysis unit to produce “Brown's gas” by electrolysis of water.

WO 2012/162434 also describes electrolysis apparatus having parallel conductive plates and a series of intermediate neutral plates. This document also describes a gas generator in which the plate arrangement is immersed in water and generates hydrogen and oxygen gas on application of an external voltage.

GB 2 020 697 describes further electrolysis apparatus including parallel electrodes with a intervening passive plates, and the use of this apparatus in the production of oxyhydrogen gas by electrolysis of water.

SUMMARY

The present invention relates to an improved electrode for use in electrolysis apparatus. The electrode may be useable as any or all of an anode, cathode, or passive plate in an electrolytic cell.

The improved plate of the present invention comprises a planar electrically conductive plate wherein at least part of one face of the plate is covered with a plurality of electrically conductive wires each of which is in electrically conductive contact with the surface of the plate along at least part of its length. Preferably the plurality of electrically conductive wires form a wire mesh.

The present proposals also relate to an electrode array comprising one or more electrodes as described herein. Preferably the electrode array comprises a plurality of electrodes as described herein. Preferably the spacing between adjacent electrodes is about 9 mm.

The present proposals also relate to an electrolytic cell comprising an electrode or electrode array as described herein. Preferably the electrolytic cell also includes an electrolyte. Preferably the electrolyte comprises water.

These proposals also relate to a method of generating oxyhydrogen gas using such an electrode, electrode array or electrolytic cell as described herein. Furthermore, the proposals relate to methods of supplying oxyhydrogen gas generated according to the methods described herein to an internal combustion engine.

Use of an electrode, electrode array or electrolytic cell as described herein allows greater efficiency in the generation of oxyhydrogen gas. In particular, one or more of the following benefits may be achieved:

the vaporisation of water during the electrolysis process may be reduced;

the working temperature of the system may be controlled or reduced; and

the amount of gas produced for a given power consumption can be increased, i.e. the efficiency of gas production is increased and energy wastage reduced.

Preferred apparatus and conditions may produce increased amounts of the advantageous product “Brown's gas”. Brown's gas has been reported as having some beneficial properties that may differ from a 2:1 hydrogen:oxygen mixture, including reports of higher temperature produced by a combustion flame of Brown's gas when impinged on a substrate.

BRIEF DESCRIPTION OF FIGURES

FIG. 1 shows a partial view of an electrolytic cell incorporating plates as described herein.

FIG. 2 shows a cutaway view of an electrolytic cell incorporating plates as described herein and showing the dimensions of this embodiment.

FIG. 3 shows an end view of an electrolytic cell incorporating plates as described herein and showing the dimensions of this embodiment.

FIG. 4 shows an end view (opposite end to FIG. 3) of an electrolytic cell incorporating plates as described herein and showing the dimensions of this embodiment.

FIG. 5 shows a view (from underneath) through an electrolytic cell incorporating plates as described herein.

FIG. 6 shows a plan of a positive electrode plate as described herein showing the dimensions of this embodiment.

FIG. 7 shows a plan of a passive plate as described herein showing the dimensions of this embodiment.

FIG. 8 shows a plan view of a seal to fit around the edge of a plate as described herein to create a seal against an outer housing. Also shown are the dimensions of this embodiment.

FIG. 9 shows an edge view of a seal to fit around the edge of a plate as described herein to create a seal against an outer housing. Also shown are the dimensions of this embodiment.

FIG. 10 shows an end view of an outer housing tube as described herein with the dimensions of this embodiment also shown.

FIG. 11 shows a side view of an outer housing tube as described herein with the dimensions of this embodiment also shown.

FIG. 12 shows a schematic of the arrangement of anode, cathode and passive plates in one embodiment.

DETAILED DESCRIPTION

The present proposals relate to an electrode for use in electrolysis apparatus. The electrodes comprise an electrically conductive plate and at least part of one face of the plate has electrically conductive wires arranged on it. The electrically conductive wires are in electrical contact with the surface of the plate along at least part of the length of the wire.

The plate itself may be made from any electrically conductive material, e.g. a metal, carbon, or a conductive polymer, compound or composite. Preferably the plate is made from a metal, more preferably a metal selected from steel, copper, lead, platinum. Most preferably the plate is made from steel (e.g. stainless steel with Ni).

The shape of the plate is not particularly limited but the perimeter of the plate is preferably square, rectangular, circular or oval, most preferably circular.

The plate may also have various apertures therethrough to allow mounting in apparatus, e.g. in an electrode array.

The wires covering at least part of the surface of the plate preferably make electrical contact with the surface of the plate along at least part of the length of each wire. Preferable the wires are in electrical contact with the surface of the plate in at least two positions along the length of each wire, most preferably at each end of each wire.

Preferably the wires are arranged in a regular pattern on the surface of the plate, e.g. in parallel evenly spaced rows. The wires may also be arranged over at least part of both faces of the plate, preferably the whole of both faces of the plate.

Preferably the wires form part of a wire mesh which covers at least part of one face of the plate, preferably at least part of both faces of the plate. The wire mesh may cover all of one face of the plate, and preferably all of both faces of the plate.

The wires, or wires in the mesh, preferably have a diameter of about 0.1-0.5 mm, most preferably 0.25 mm.

The spacing between the wires, or spacing between the wires in the mesh, is preferably about 0.1-1.5 mm, more preferably 0.1-1 mm, more preferably 0.2-0.8 mm, most preferably about 0.4 mm.

A preferred wire mesh has wires defining quadrilateral, or preferably parallelogramatical, most preferably square or rhombic, spaces between them. The spaces are preferably square or rhombic, most preferably square, with side length of about 0.1-1.5 mm, more preferably 0.1-1 mm, more preferably 0.2-0.8 mm, most preferably about 0.4 mm. When a wire mesh having these properties is used, in particular a wire mesh defining square spaces between the wires with a side length of about 0.4 mm, gas production and release of gas from the surface of a plate including such a mesh when used in electrolysis, is improved. In particular, when a mesh having these properties is used gas production is notably high and gas is released easily from the surface of the electrode.

If the size of the spaces in the mesh, or the spacing of the wires, is smaller than the minimum values mentioned above, the gas does not release as easily from the surface of the plate and gas production is hindered. On the other hand, if the size of the spaces in the mesh, or the spacing of the wires, is larger than the maximum values mentioned above, the surface area of the electrode is reduced which results in lower gas production from a given size of plate.

The surface of the plate is preferably treated to increase the specific surface area, i.e. the surface area per unit mass of the plate. For example, the surface of the plate is preferably scratched, etched, sand- or shot- blasted. Alternatively the plate is corrugated to increase the specific surface area. In preferred aspects, the plate is scratched. Preferably the plate is scratched with sandpaper (e.g. 60 grit sandpaper with average particle size 265 μm), preferably with scratching strokes at 90 degrees to each other.

Increasing the specific surface area of the electrode results in an increased capacitance when the electrode is used in conjunction with another electrode in an electrolysis apparatus. This increased capacitance results in a lower voltage between the plates for a given charge (or a larger charge on the plates for a given voltage). The lower voltage means a lower current for a set resistance of the system and consequently an advantageous lower power consumption and lower heat generation.

The plate preferably has an aperture therethrough to allow gas that is produced by electrolysis using the electrode to pass freely through the electrode. In situations where an array of electrodes is used and particularly where the array is arranged in a housing which forms a close seal around the edges of the plates, this allows any gas produced to pass through the electrode and collect inside the top of the apparatus.

A further aspect of the present proposals is an electrode array comprising at least one electrode as defined herein, preferably a plurality of electrodes as defined herein. In most preferred aspects, all of the electrodes (cathodes, anodes and passive electrodes) in the array are electrodes as defined herein.

The electrode plates in the array are preferably aligned with the faces of the plates opposed. In more preferred aspects, each plate has an aperture therethrough and the apertures are preferably aligned.

In these electrode arrays, at least two (e.g. 2, 3, 4, 5, 6, 7, 8, 9, 10, or more) of the electrodes may comprise a connection region, e.g. a connector element, to connect the electrode to an external power source. In some arrangements the electrodes comprising the connection region are interspersed with one or more (e.g. 1 to 10, preferably 2-8, more preferably 5 or 6, most preferably 5) passive electrodes (which may be electrodes as described herein), i.e. which do not connect to the external power source.

In most preferred embodiments, the electrode array comprises four electrodes comprising a connection region to connect to an external power source, two of these electrodes form cathodes and alternate along the array with the other two of these electrodes that form anodes when connected to an external power source, wherein five passive electrode plates as defined herein are interspersed between each cathode and anode. This number of cathodes, anodes and passive electrodes provides a high capacity for oxyhydrogen production when the array is used in the electrolysis of water coupled with a reasonably low power consumption, i.e. a high gas production efficiency of an electrolysis apparatus using such an electrode array.

The spacing between adjacent electrodes in an electrode array according to these proposals is preferably between 1 and 20 mm, preferably between 2 and 15 mm, more preferably between 5 and 10 mm, most preferably about 9 mm. The preferred 9 mm spacing can achieve a good balance between the rate of gas production and reasonably low electrical power consumption (the rate of gas production per watt of electrical power is high). Furthermore, there are indications that high levels of the advantageous product “Brown's gas” can be produced in systems using this 9 mm electrode spacing; larger or smaller spacing typically produce lower levels of “Brown's gas”.

A smaller spacing between the adjacent electrodes results in a lower capacitance and hence a larger voltage between the plates (or a larger charge on the plates for a given voltage). This in turn typically results in a larger current between the plates for a set resistance and hence a higher power consumption and higher heat generation but also a higher capacity for gas generation in electrolysis apparatus. While a larger electrode spacing results in lower power consumption, the gas generation capacity is also lower. So the plate spacing is a balance between detrimental higher power consumption and heat generation but advantageous higher gas generation capability associated with small spacing between the plates; and advantageous lower power consumption and heat generation but also lower gas generation capability associated with larger spacing between plates. The use of electrodes and electrode arrays as described herein with the electrode spacing as described, particularly a spacing of 9 mm, allow a surprisingly good balance of these advantages and disadvantages to be achieved; high gas production capabilities can be achieved with low heat generation and power consumption. Furthermore, the spacing between the plates has an impact on the overall physical size of electrolysis apparatus. Use of the present electrodes provides electrolytic apparatus having high gas generation efficiency, i.e. high gas generation rate per unit volume of the overall electrolytic apparatus.

The present proposals also relate to electrolytic cells incorporating an electrode or electrode array as defined herein. Preferably the electrode or electrode array is mounted in a housing which encases the electrode or electrode array and which contains an electrolyte in which the electrode or electrode array is at least partially immersed. The housing preferably has an aperture in fluid communication with a space above the level of the electrolyte. This allows removal from the housing of any gas generated by the electrolysis of the electrolyte.

The electrolytic cell preferably includes a gasket around at least part of the edge of the electrode or of each electrode in the electrode array and forming a fluid-tight seal with the housing. In preferred aspects, this gasket is present around the entire circumference of the electrode or of each electrode in the electrode array. Such an arrangement creates pockets for electrolyte between each pair of electrodes, the fluid-tight seal with the housing around the edge of the electrode(s) providing a barrier to fluid flow from one side of the electrode(s) to the other within the housing around the seal.

Preferably the gasket around the edge of the electrode is made from a resilient material, e.g. rubber or silicone. In some preferred aspects, the gasket has a U-shape cross section and the edge of the electrode plate fits into the channel of the U-shape. Preferably when used with an electrode which has wires or a wire mesh attached to the electrode at the edge of the plate, such a U-shape gasket covers the end(s) of the wires or mesh at the edges of the electrode plate. Where the end(s) of wires or a wire mesh is attached to the surface of the electrode plate, e.g. by welding, the attachment point may provide non-uniform regions on the electrode plate surface which can focus electrical field lines and result in non-uniform gas production from such an electrode when used in an electrolysis apparatus. Therefore, the use of a U-shaped gasket around the edge of the electrode plate and covering the regions of attachment of the wire(s) or mesh to the plate, provides a generally more uniform surface of the electrode plate and more uniform gas generation across the electrode plate surface when used in an electrolysis apparatus.

In an electrolytic cell as described herein, the electrodes preferably all have an aperture therethrough and the apertures are preferably aligned. Furthermore, the apertures are preferably above the level of the electrolyte in the electrolytic cell. This allows any gas produced in the electrolytic cell to collect above the electrolyte and to flow between the electrodes in a space above the electrolyte. This prevents uneven gas build-up between different electrodes in the electrolytic cell.

The electrolyte in an electrolytic cell as described herein may be selected from organic liquids and aqueous liquids, and is preferably an aqueous liquid such as an aqueous solution. In preferred aspects, the electrolyte is an aqueous solution of an ionic salt, such as aqueous NaOH or KOH solution. The electrolyte may contain an ionic salt in aqueous solution at a weight ratio of between 1:1 and 1:10, preferably about 1:4 ionic salt:water.

The use of an aqueous electrolyte allows production of useful oxyhydrogen gas by electrolysis of the water in the electrolyte.

The present proposals also relate to methods of generating oxyhydrogen gas using an electrolytic cell as described herein, the method comprising passing an electric current via the electrode or electrode array through an electrolyte comprising water.

In these methods, the electric current is a DC current. The potential difference across the electrolytic cell is preferably between 10 and 20 volts, more preferably between about 10 and 16 volts, more preferably between about 12 and 14 volts or between 13.8 and 14.2 volts, most preferably about 14 volts. This defines the voltage across the whole cell so the voltage across each pair of electrodes in the cell may be considerably lower. In preferred aspects, the voltage across each pair of adjacent electrodes (including any passive electrodes) is between 2 and 3 volts, preferably between 2.2 and 2.5 volts, more preferably between 2.3 and 2.4 volts, most preferably between 2.3 and 2.37 volts.

The current through the electrolytic cell in the continuous current mode is preferably between 10 and 130 Amperes, preferably between 10 and 30 Amperes or between 15 and 90 Amperes, more preferably between 15 and 60 Amperes, most preferably between 18 and 22 Amperes, such as about 20 Amperes. In this continuous supply mode, the preferred supply to the electrolytic cell is at 14 volts and 20 Amperes. Under these preferred conditions, high rates of gas production and high efficiency of the cell may be observed.

In the pulsed current mode, the current through the electrolytic cell may depend on the pulse characteristics but is preferably between 1 and 30 Amperes, more preferably between 1 and 20 Amperes, preferably between 5 and 15 Amperes, most preferably between 8 and 12 Amperes, e.g. about 10 Amperes.

The current applied in these methods may be a pulsed DC current. The preferred frequency of the pulses is about 50 Hz-10 KHz, preferably 100 Hz-5 KHz, more preferably 500 Hz-2 KHz, most preferably about 1 KHz. The pulse occupancy is preferably about 10%-90%, preferably 25%-75%, more preferably 40%-60%, most preferably about 50%. Use of a pulsed DC current at about 1 KHz with a pulse occupancy of about 50% in an electrolytic cell with an aqueous electrolyte has the advantage that it may produce oxyhydrogen gas at high rate. Furthermore, this pulsed DC current (1 KHz, 50% pulse occupancy) may advantageously produce “Brown's gas”.

A non-limiting embodiment of the present invention is shown in FIGS. 1-11.

FIG. 1 shows a partial view of an electrolytic cell of the invention which has an end plate 1 which supports dowel rods 9 that link to another end plate (not shown) to provide the overall framework for the electrode plates 2, 3. Both end plates are held in place by washers 8 and nuts 7 on a threaded end of the dowel rods 9. The cell includes active cathode/anode electrodes 2 and passive electrodes 3 that are linked together by further dowel rods 10, 12 which pass through apertures in the electrodes. The dowel rods 10, 12 pass through the electrode at each end of the array and are secured in place with a nut 13 on a threaded end of the dowel rod. The dowel rods 10, 12 include spacer elements 4 to set the spacing between adjacent electrodes. Intermediate nuts 6, 11 along the length of the dowel 10, 12 hold the electrode plates 2, 3 and spacers 4 in the required positions relative to each other. Each electrode has a sealing gasket 5 around the edge of the electrode plate. These sealing gaskets 5 seal against the inside surface of a housing tube (not shown) that fits around the electrodes and sealing gaskets inside the dowel rods 9.

Dimensions of the overall cell are shown in FIG. 2 which also shows both end plates in place. One end view showing dimensions is shown in FIG. 3 and the opposite end view is shown in FIG. 4.

A view from underneath the cell is shown in FIG. 5 showing the arrangement of dowel rods and plates along the cell.

FIG. 6 shows a plan of a positive electrode plate showing dimensions and apertures for the dowel rods. This also shows the larger aperture at one side of the plate which allows gas to pass through the plate. FIG. 1 shows alignment of these apertures in each electrode plate to allow gas to pass along the length of the entire cell.

A plan of a passive electrode plate with dimensions is shown in FIG. 7. Again, the large aperture at one side of the plate is shown which allows gas to pass through the plate. This aperture is a different shape to that in the positive electrode plate of FIG. 6 because the passive electrode does not need to provide a connection region for connection of the electrode to an external power supply.

FIGS. 8 and 9 show plans of a top view and edge view respectively of a seal gasket to fit around the edge of the electrode plates to form a seal against an outer housing. Again, the dimensions are also shown. FIG. 9 shows the U-shape profile of the seal gasket which allows it to fit around the edge of the electrodes and overlap onto the face of the plate by a small amount. As noted above, this provides the advantage that the seal gasket can cover the regions where the wires or wire mesh is attached to the surface of the electrode plate.

FIGS. 10 and 11 show an end view and side view respectively of the outer housing tube with the dimensions also shown. As noted above, this outer housing tube fits around the electrode plates but inside the dowel rods 9 as shown in FIG. 1.

A schematic arrangement of the anode, cathode and passive electrode plates is shown in FIG. 12. The preferred arrangement is shown of two cathodes alternating with two anodes interspersed with five passive electrodes between each anode/cathode pair. As noted above, this arrangement can provide high oxyhydrogen gas production on water electrolysis with low power consumption and low heat production in an apparatus having a high gas production per unit volume of apparatus.

EXAMPLES

An electrolytic cell as shown in FIGS. 1-11 was used in the following examples.

Example 1, Comparative Example 1 Oxyhydrogen Generation

The electrolytic cell shown in FIGS. 1-11 was filled with 2100 ml electrolyte fluid; up to a level 99.5 mm from the bottom of the generator (of the pipe casing) and 11.8 mm below the base of the holes at the top of the electrode and passive plates ensuring that the spaces between each plate in the cell were filled to about the same level.

The electrolyte was a solution of NaOH in distilled water at a ratio of 1:4 NaOH:water.

The cell consisted of three consecutive sets of seven parallel plates each set having an anode and a cathode at opposing ends with five passive plates arranged between them arranged as shown in FIG. 12.

The spacing between adjacent plates is 9 mm throughout the cell.

All plates are made from stainless steel (Grade 316L). Both faces of each plate are scratched prior to use with 60 grit sandpaper (average particle size 265 μm) with scratching strokes at 90 degrees to each other. Both faces of each plate are covered with steel mesh with the same shape and dimensions as the face of the plate, with the exceptions of the plate at each end of the electrode array which is covered with the mesh only on the face opposed to the next electrode (i.e. the “inner” face). The steel mesh is made from the same grade of steel as the plates (Grade 316L). The thickness of the wires making up the mesh is 0.25 mm and the spacing between adjacent wires is 0.40 mm. The steel mesh is welded to the plate around the edge of each plate.

A rubber seal of a grade resistant to alkaline solutions as shown in FIGS. 8 and 9 is fitted around the edge of each plate and covers the area where the steel mesh is welded to the face of each plate.

The array of plates is fitted into a steel (Grade 316L) tubular outer housing with connections established to the cathode and anode plates. The rubber seal around the edge of each plate creates a seal against the outer tubular housing preventing the electrolyte from moving between adjacent spaces between the plates.

A variety of different potential difference values were tested (as shown in Table 1 below). Preferred embodiments had a potential difference of 2.3-2.37 V is established across each pair of adjacent plates. This corresponds to a potential difference of 13.8-14.2 V across each set of seven plates, i.e. between consecutive anode/cathode pairs, using an external power source. [The 13.8-14.2 V overall potential difference across the consecutive anode/cathode pairs is divided by the six spaces between adjacent plates to give a potential difference of 2.3-2.37 V across each pair of adjacent plates). The DC current varied with the voltage due to the overall resistance of the cell as shown in Table 1 below.

The apparatus generated oxyhydrogen gas which accumulated in the space above the electrolyte in the apparatus and was collected from this space.

Oxyhydrogen gas with a 2:1 ratio of hydrogen:oxygen was produced under conditions shown in table 1.

TABLE 1 (Example 1) Gas L/h Voltage Current production Power per (V) (A) rate (L/h) (Watts) Watt 12 27.75 128 333 0.38 14 58.5 283 819 0.34 16 92.25 521 1476 0.35 18 122.25 610 2200 0.27 18.5 129.75 654 2400 0.27

These results are compared with results, shown as “Comparative Example 1”, from similar apparatus but using electrodes which did not have the wire mesh covering. These results are shown in table 2.

TABLE 2 (Comparative Example 1) Gas L/h Voltage Current production Power per (V) (A) rate (L/h) (Watts) Watt 12 17.5 49 210 0.23 14 45 193 630 0.31 16 78 363 1248 0.29 18 130 500 2340 0.21 18.5 144 553 2664 0.21

Comparison of tables 1 and 2 shows the improved efficiency of the electrolytic cell according to the present invention as compared to similar apparatus without the wire mesh covering on the electrodes.

Example 2, Comparative Example 2

An electrolytic cell as used in Example 1 was operated under the same conditions (potential difference of 13.8-14.2 V across each set of seven plates and a DC current through each set of seven plates which varied with the voltage due to the overall resistance of the cell) but in this example, a pulsed DC current was used at a frequency of 1 KHz and a pulse occupancy of 50%.

Oxyhydrogen at a ratio of 2:1 hydrogen:oxygen was produced as shown in Table 3.

TABLE 3 (Example 2) Gas L/h Voltage Current production Power per (V) (A) rate (L/h) (Watts) Watt 12 1.7 5 20.4 0.25 14 5.8 24.08 81.2 0.30 16 10.4 57.14 166.4 0.34 18 15.5 66.66 279 0.24 19 17.6 76.59 334.4 0.23

These results are compared with results, shown as “Comparative Example 2”, from the same apparatus but using electrodes which did not have the wire mesh covering. These results are shown in table 4.

The gas produced under these conditions is predominantly “Brown's Gas” which accumulated in the space above the electrolyte in the apparatus and was collected from this space.

TABLE 4 (Comparative Example 2) Gas L/h Voltage Current production Power per (V) (A) rate (L/h) (Watts) Watt 12 2.8 2.67 33.6 0.08 14 4.6 8.89 64.4 0.14 16 9.0 25.80 144 0.18 18 20.05 74.20 360.9 0.21 19 29.5 100 560.5 0.18

Comparison of tables 3 and 4 shows again the improved efficiency when operated under pulsed DC current of the electrolytic cell according to the present invention as compared to similar apparatus without the wire mesh covering on the electrodes. 

1. An electrode for an electrolysis apparatus comprising a planar electrically conductive plate wherein at least part of one face of the plate is covered with a plurality of electrically conductive wires each of which is in electrically conductive contact with the surface of the plate along at least part of its length.
 2. An electrode according to claim 1, wherein the plurality of electrically conductive wires form part of an electrically conductive mesh covering at least part of one face of the plate.
 3. An electrode according to claim 2, wherein the wires in the mesh have a diameter of 0.1-0.5 mm and the wires define quadrilateral spaces between them with side lengths of about 0.2-0.8 mm.
 4. An electrode according to claim 1, wherein the electrically conductive plate has an aperture therethrough.
 5. An electrode array comprising a plurality of electrodes as defined in claim 1 aligned with the faces of the plates opposed.
 6. An electrode array according to claim 5, wherein at least two of the electrodes comprise a connector to connect the electrode to a power source, and wherein one of these electrodes forms an anode and one of these electrodes forms an anode hen connected to an external power source.
 7. An electrode array according to claim 6, wherein the electrodes comprising a connector are interspersed with one or more passive electrodes.
 8. An electrode array according to claim 7, wherein the array comprises two electrodes that form cathodes alternating along the array with two electrodes that form anodes when connected to an external power source, and wherein five passive plates are interspersed between each cathode and anode.
 9. An electrode array according to claim 5, wherein the spacing between adjacent electrode plates is between 5 mm and 10 mm.
 10. An electrode array according to claim 9, wherein the spacing between the electrode plates is about 9 mm,
 11. An electrolytic cell comprising an electrode according to claim 1 or comprising an electrode array having a plurality of electrodes aligned with the faces of the plates opposed.
 12. An electrolytic cell according to claim 11, further comprising a housing which encases electrode or electrode array, wherein the housing contains an electrolyte in which the electrode or electrode array is at least partially immersed, and wherein at least part of the edge of the electrode or of each electrode in the electrode array forms a fluid-tight seal with the housing so providing a barrier to fluid flow from one side of the electrode to the other within the housing around the seal.
 13. A method of generating oxyhydrogen gas using an electrolytic cell according to claim 11, the method comprising passing an electric current via the electrode or electrode array through an electrolyte comprising water.
 14. A method according to claim 13, wherein the electric current is a DC current; the potential difference across the electrolytic cell is between 10 and 20 volts and the current is between 10 and 30 Amperes.
 15. A method of claim 13, further comprising supplying the oxyhydrogen gas to an internal combustion engine.
 16. (canceled) 